Mobile robots are nowadays becoming popular for performing simple and repetitive tasks, such as household maintenance (floor cleaning), or dangerous tasks, for instance inspection or surveillance activities inside environments where humans are at risk.
Typically, mobile robots may be controlled remotely by a human operator or they may operate autonomously. This latter type of operation implies that the mobile robot is capable of autonomous indoor navigation, which means that the robot is capable of creating a map of the indoor environment, determining its localization within the map and planning a path to navigate point-to-point within the map.
Generally, an autonomous mobile robot may be provided with electric traction motors. In this case, it is also provided with an on-board power unit (i.e. a battery) that is periodically recharged. Recharging is performed at a docking station connected to the electric power distribution network. When the on-board battery is to be recharged, the autonomous mobile robot typically moves towards the docking station. In the vicinity of the docking station, the mobile robot starts a docking operation according to which the mobile robot determines the exact position of the docking station and generates motion commands for its traction motors, in order to approach the docking station and connect to it. Typically, the position of the docking station may be determined by the mobile robot by detecting, through appropriate sensors, signals emitted by the docking station, which may comprise infrared beacons and light signals, or by recognizing reference images or visual markers located on the docking station, or by detecting an audio marker emitted by the docking station or by a sound source in the vicinity of the docking station.
WO2014/114910 discloses a docking station for a mobile robot comprising a base portion that is locatable on a floor surface and a rear portion that is pivotable with respect to the base portion, thereby permitting a user to place the docking station on the floor in an unfolded configuration but to store the docking station in a folded configuration.
EP2617531A1 discloses an intelligent robot system comprising an intelligent robot and a charging base. The intelligent robot comprises a docking electrode, a walking mechanism and a control unit. The docking electrode, the walking mechanism and the control unit are disposed in the body of the intelligent robot. The charging base comprises a charging electrode disposed on the body of the charging base. The intelligent robot further comprises a gripping mechanism. When the docking electrode and the charging electrode dock successfully, the control unit controls the gripping mechanism to lock the walking mechanism to enable the intelligent robot to maintain a successful docking state in the charging base, preventing the charging electrode of the charging base from being separated from the docking electrode due to the improper movement of the walking mechanism. Any interference during of the intelligent robot is thus prevented and charging efficiency is improved.
U.S. Pat. No. 7,546,179 discloses a method and apparatus allowing a mobile robot to return to a designated location the method including: calculating a first direction angle of the mobile robot at a second location arrived at after the mobile robot travels a predetermined distance from the first location; determining whether the mobile robot approaches or moves away from the designated location, at a third location arrived at after the mobile robot rotates by the first direction angle and then travels a predetermined distance; and if the result of the determination indicates that the mobile robot approaches the docking station, controlling the mobile robot to travel according to the first direction angle, and if the result indicates the mobile robot moves away from the docking station, calculating a second direction angle of the mobile robot at the third location, and controlling the mobile robot to travel according to the second direction angle.
U.S. Pat. No. 7,332,890 discloses a method for energy management in a robotic device includes providing a base station for mating with the robotic device, determining a quantity of energy stored in an energy storage unit of the robotic device, and performing a predetermined task based at least in part on the quantity of energy stored. Also disclosed are systems for emitting avoidance signals to prevent inadvertent contact between the robot and the base station, and systems for emitting homing signals to allow the robotic device to accurately dock with the base station.